/* target - bullseye
 */


surface
target (color baseColor = color "rgb" (.4, 0, .6);
        color targetColor = color "rgb" (0, 1, 0);
        point center = point "camera" (0, 0, 0);
        float range = 2; )        
{
    Oi = Os; 

    if(distance(P, center) <= range) 
        Ci = Oi * targetColor;
    else
        Ci = Oi * baseColor; 
}
